Belief in the bloodsucker Tlahuelpuchi is prominent in the Mexican state of Tlaxcala, with deep roots amongst the indigenous Nahua culture of the region.
The word tlahuelpuchi derives from the Nahuatl tlāhuihpochtli (plural tlātlāhuihpochtin), a compound of tlāhuia, "to light up or illuminate" and pōchtli, which can mean "haze", "left", "southern" or "youth" (as in compounds like tēlpōchtli, young man).
The typical sign that a victim was killed by the tlahuelpuchi are bruises on their upper body.
Tlahuelpuchi are able to change form by detaching their body from their legs (which are left in the house of the witch).
The tlahuelpuchi must fly over the house in the shape of a cross from north to south, east to west.